The present invention pertains to a method for coding and decoding an information symbol or stream of information symbols to be transmitted across a transmission channel. Furthermore, the invention pertains to devices for encoding a signal to be transmitted and decoding a signal value received.
Transmission channels must generally deal with echoes, multipath propagation, preoscillation and postoscillation. These effects result in inter-symbol interference (ISI) between symbols occurring consecutively in time. In the general case, it is not possible to invert the transfer function of the transmission channel and thereby eliminate the perturbing influence of the transmission channel.
It is known that the perturbing influence of the transmission channel can be reduced by devices at the receiver side, such as equalizers or maximum likelihood sequence estimation.
At the sending side of a transmission system, precoding represents a way of reducing the perturbing influence of ISI caused by the transmission channel. Based on the Tomlinson Method as described by M. Tomlinson in “New Automatic Equalizer Employing Modulo Arithmetic,” Electronics Letters, 25 Mar. 1971, Vol. 7, pp. 138-139, numerous investigations have been conducted on the topic of precoding and various precoding variants have been developed.